The present invention relates to a cassette tape player for recording and/or reproducing a compact cassette tape.
FIG. 1 shows a known compact cassette tape (which will be hereinafter referred simply to as a cassette) in perspective. As well known in the art, such a cassette has a standardized construction including a magnetic head insert opening 1 adapted to receive a magnetic head upon loading the cassette into a cassette tape player, two pinch roller insert openings 2a and 2b adapted to receive two pinch rollers (and erasing heads in some kinds of cassette tape player), two capstan insert holes 3a and 3b adapted to receive two capstans, two openings 4a and 4b adapted to receive two erasing heads particularly in a reversible record/playback type cassette tape player, and two guide holes 5a and 5b adapted to receive two guide projections. Further, there is provided a pad 6 inside the magnetic head insert opening 1 in such a manner as to be urged toward a tape T.
FIG. 2 is an exploded view of the cassette shown in FIG. 1. As shown in FIG. 2, a magnetic shielding plate 7 is provided behind the pad 6 inside the magnetic head insert opening 1, so as to obtain a magnetic shielding effect.
FIGS. 3A to 3D schematically show head mounting sections in different types of conventional cassette tape players in relation to the above-mentioned cassette. As apparent from FIGS. 3A to 3D, the openings and the holes of the cassette are differently used depending upon the types of the cassette tape players. More specifically, the cassette tape player shown in FIG. 3A is of a one-way playback-only type including a magnetic head (reproducing head) 11, a pinch roller 12, a capstan 13, and two guide projections 15. The cassette tape player shown in FIG. 3B is of a one-way record/playback type including a magnetic head (recording/reproducing head) 11, a pinch roller 12, a capstan 13, an erasing head 14, and two guide projections 15. The cassette tape player shown in FIG. 3C is of a reversible playback-only type including a magnetic head (reproducing head) 11, two pinch rollers 12a and 12b, two capstans 13a and 13b, and two guide projections 15. The cassette tape player shown in FIG. 3D is of a reversible record/playback type including a magnetic head (recording/reproducing head) 11, two pinch rollers 12a and 12b, two capstans 13a and 13b, two erasing heads 14, and two guide projections 15.
In general, the reproducing head or the recording/reproducing head in the head mounting section is adapted to be inserted into the magnetic head insert opening 1 of the cassette and be brought into pressure contact with the tape T by utilizing the pad 6.
The two guide projections 15 are adapted to be inserted into the guide holes 5a and 5b of the cassette. As shown in FIG. 4A, each guide projection 15 is formed on a chassis 16 of the cassette tape player, and has a substantially conical shape, for example. As shown in FIG. 4B, when the cassette is loaded into the cassette tape player, the two guide projections 15 are inserted into the rectangular guide holes 5a and 5b in such a manner that a cylindrical portion of each guide projection 15 contacts an inner wall surface of the corresponding guide hole 5a (5b) at three points, thereby positioning the cassette in the head mounting section.
In the reversible type cassette tape player as shown in FIGS. 3C and 3D, the two pinch rollers 12a and 12b and the two capstans 13a and 13b are used for constant-speed running of the tape in a forward (normal) direction and a reverse direction. However, in consideration of a reduction in number of parts, lightness in weight, compactness, singularity of a motor, and simplicity of a drive transmitting system in the cassette tape player, it is preferable to adopt a so-called single capstan reversible type such that a single capstan and a single pinch roller cooperating therewith are employed to drive the tape T in both the normal and reverse directions.
In this circumstance, there has been proposed a single capstan reversible type cassette tape player constructed by removing the capstan 13b and the pinch roller 12b from the construction shown in FIGS. 3C and 3D and adopted the capstan 13a and the pinch roller 12a so that the capstan 13a can be driven in both the normal and reverse directions.
However, in such a single capstan reversible type cassette tape player as proposed above, there occurs a serious problem in practical use such that while the tape T fed by the capstan 13a in the reverse running is recorded or reproduced by the magnetic head 11, the travel of the tape T as well as the tape path becomes unstable, and the tape T is apt to stick to the magnetic head 11.
To solve this problem, it has been proposed to increase a take-up torque in the reverse running. However, this technique is not effective and causes a problem in practical use such that power consumption increases and wow/flutter also increases (particularly, since a component in a take-up system is not blocked by the pinch roller and the capstan, it is more disadvantageous to increase the take-up torque).